The present invention relates to a printer having a plurality of individually swingable printing character bearing belts cooperating with a platen for printing a line of printing of desired characters on a paper by selectively swinging the printing belts upon issuance of printing signals from a control circuit of the printer so as to cause the belts to abut against the platen with the paper held therebetween after selection of a desired character on each printing belt during the rotation thereof around a pair of wheels stretching each belt therearound.
Different from the prior art printer of the type having a plurality of individually swingable printing rings for each figure or number, for example, which are selectively abutted against a platen when a selected character is positioned at a printing position on each printing ring for the printing operation, the printer of the present invention provides a respective printing belt which is stretched around a pair of wheels supported by a wheel supporting swingable lever with one of the wheels driven by a driving shaft for rotation of the belt so as to select a desired character on the belt while the other wheel is adapted to move against a platen when a desired character is selected by the swinging of the wheel supporting lever for effecting the printing on a paper held therebetween. The swinging of each wheel supporting lever is controlled by a driving lever which is in turn controlled by a select lever and an electromagnet cooperating therewith and actuated by a printing signal from the control circuit of the printer while the driving shaft continues to rotate thereby permitting printing of a line of the desired characters on a paper in cooperation with the platen, and, after completion of the printing operation, the respective printing belt is returned by a spring so as to restore the belt to its initial position when the driving lever is returned to its initial position through a reset cam driven by the driving shaft and moving it to the initial position in readiness for the next printing operation.
Since the prior art printer having a plurality of printing rings is very complicated in construction and troublesome in assembly requiring the preparation of two kinds of materials for constructing the printing rings having resilient nature of each printing character for permitting the clear printing. Further, the printing rings have disadvantages in that the number of printing characters to be born thereon is limited.
The present invention aims at avoiding the above described disadvantages of the prior art printer.
The above object is achieved in accordance with the present invention by providing a printer having a plurality of swingable and rotatable printing character bearing endless belts cooperating with a platen for the printing operation, characterized by a swingable supporting member for supporting each of the printing belts so as to rotate the printing belt around itself on the supporting member, a driving shaft for transmitting the driving force to the respective printing belt for the rotation thereof around itself, one of the plurality of printing characters born on the periphery each of the printing belt being selected for the desired printing operation by virtue of the rotation of the printing belt around itself while the printing belt is swung toward the platen for effecting the printing operation by virtue of the swinging movement of the supporting member, signal emitting means rotated in synchronism with the driving shaft, signal receiving means cooperating with the signal emitting means so as to issue an electrical signal each time one cycle of the printing operation is effected by the rotation of the driving shaft, the electrical signal being applied to a control circuit for controlling the starting and stopping of the operation of the printer, a detecting disc rotated in synchronism with the driving shaft and provided with a plurality of slits around the rotational axis thereof corresponding in number to that of the characters on the respective printing belt and a detecting device cooperating with the slits in said detecting disc for issuing character synchronizing timing signals in timed relationship to the positions of the respective moving characters on each printing belt as it rotates around itself, the timing signals being applied to the control circuit for permitting a desired character of the plurality of characters on each printing belt to be selected for the printing operation during the rotation of the respective printing belt.
The starting and terminating of one cycle of printing operation may be controlled by a magnet adapted to be rotated by one revolution by the driving shaft for one cycle of the printing operation and a detecting reed switch cooperating therewith so as to issue an electrical signal applied to the control circuit.
The character selecting and synchronizing signal may be obtained by the provision of a detecting disc having circumferentially arranged slits corresponding in number to that of the characters and rotated by the driving shaft and a detecting device cooperating with the slits so that signals corresponding to the positions of the characters on the respective printing belt are obtained which are applied to the control circuit so as to control the selection of a desired character on the respective printing belt.